You must disable the Change User Date dialog window prompt if you are running a DPS. This window can pop up at midnight and distrupt tasks that are running on your DPS or could potentially crash the DPS. To do this, you must edit the Dex.ini that's used for the DPS and add the following line:
SuppressChangeDateDialog=TRUE
The Dex.ini is normally located in the Dynamics GP installation folder or the \Data folder within the Dynamics GP installation folder. In some configurations, a specific Dex.ini might be specified as part of the shortcut that's used to launch Dynamics GP, so check the shortcut and then edit that Dex.ini.
If you are using the latest build of GP Agent, this setting will automatically be added to the dex.ini for you.